Dental composition and method

ABSTRACT

The invention relates to a dental composition and methods of use of the dental composition. More specifically, the invention relates to a dental composition for an animal wherein the composition comprises algae. The invention also relates to methods of use of the dental composition comprising algae, including methods of reduction of plaque on at least one tooth of an animal.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application No. 61/205,633, filed Jan. 22, 2009, which is expressly incorporated by reference herein. This application also claims the benefit of priority to European Patent Application No. 09151157.6, filed Jan. 22, 2009, and Canadian Patent Application No. 2,673,636, filed Jul. 21, 2009, which are expressly incorporated by reference herein.

FIELD OF THE INVENTION

The invention relates to a dental composition and methods of use of the dental composition. More particularly, the invention relates to a dental composition for an animal wherein the composition comprises algae. The invention also relates to methods of use of the dental composition comprising algae, including methods of reducing plaque on at least one tooth of an animal.

BACKGROUND AND SUMMARY OF THE INVENTION

Biofilm, dental plaque, and calculus, etc. are associated with bad breath and with major dental diseases, such as dental caries, gingivitis, periodontitis, and other periodontal diseases, that affect a large percentage of animals each year. Microorganisms, such as bacteria, can contribute to formation of biofilm, plaque, and calculus. Some of the types of microorganisms that are primary, secondary, or tertiary colonizers of biofilm (e.g. dental plaque, calculus, etc.) are Streptococcus mutans, Streptococcus sanguis, Actinomyces viscosus, Lactobacillus acidophilus, Actinobacillus actinomycetemcomitans, Eikenella corrodens, Porphyromonas gingivalis, Prevotella intermedia, Bacteroides forsythus, Campylobacter rectus, Treponema denticola, Fusobacterium nucleatum, Capnocytophypa species, Tannerella species, Peptostreptococcus species, Endodontalis species, and Escherichia species.

The formation of biofilm, plaque, and calculus is not only associated with a variety of dental diseases, including dental caries, tooth loss, and periodontitis, but can lead to poor health generally in animals by contributing to the development of systemic diseases of major organ systems such as kidney disease, vascular diseases, and heart disease. Accordingly, there is a need for effective methods of reduction of biofilm, plaque, and calculus on the teeth of animals to improve animal dental health, and to improve animal health generally.

The present invention is directed to the surprising discovery that compositions comprising algae (e.g., green algae) reduce plaque on the teeth of animals. In fact, plaque reduction can occur, for example, by early times (e.g., about 24 hours) after administration of the algae composition. Algae compositions are desirable for use in such dental compositions because algae are natural, non-toxic, non-pathogenic, free of animal pathogens, easy to grow, and resistant to degradation by acids present in the mouth.

In one embodiment of the invention, a method is provided for reducing plaque on at least one tooth of an animal. The method comprises the step of causing the at least one tooth of the animal to be contacted with a composition comprising green algae wherein the composition comprising the green algae reduces the plaque on the at least one tooth of the animal. In this embodiment, the algae can be in the form of a paste, a gel, a liquid (e.g., for addition to the drinking water of the animal), a powder, a freeze-dried composition, a component of an animal treat, a nugget, a dressing for an animal food, an additive for water, a component of a chew product, or a pellet. In any of these embodiments directed to the form of the algae, the algae can be freeze-dried prior to formulating any of these compositions, and can be thawed and reconstituted to formulate the composition. Alternatively, the algae can be present in the composition in a freeze-dried form.

In illustrative aspects of any of the above-described method embodiments, the algae can be genetically modified (e.g., to express an antimicrobial peptide). In yet other illustrative embodiments of the above-described method embodiments, the algae composition can further comprise one or more of a preservative, an inert carrier (e.g., selected from the group consisting of a paste and a gel), a flavoring, a nutritional carrier, a nutraceutical, a material to enhance adhesion of the algae to at least one tooth of an animal, an antimicrobial (e.g., an antimicrobial peptide or an antibiotic), a plaque-reducing agent, and a calculus-reducing agent.

In still other illustrative embodiments of any of the above-described method embodiments, the algae can be selected from the group consisting of live algae, dead algae, and combinations thereof, or the algae can be of the species Chlamydomonas reinhardtii. In any of the above-described method embodiments, the animal treated with the algae composition can be, for example, a cat or a dog. In any of the above-described method embodiments, the algae can adhere to the at least one tooth for a prolonged period of time and the plaque can be present on more than one tooth.

In another embodiment of the invention, a composition comprising green algae is provided, wherein the green algae composition is adapted for contact with at least one tooth of an animal. In this composition embodiment, the algae can be in the form of a paste, a gel, a liquid (e.g., for addition to the drinking water of the animal), a powder, a freeze-dried composition, a component of an animal treat, a nugget, a dressing for an animal food, an additive for water, a component of a chew product, or a pellet. In another illustrative embodiment, the algae can be freeze-dried and can be capable of being reconstituted.

In another illustrative aspect of the above-described algae composition embodiment, the algae can be genetically modified (e.g., to express an antimicrobial peptide).

In yet another embodiment, the algae composition can further comprise one or more of a preservative, an inert carrier (e.g., selected from the group consisting of a paste and a gel), a flavoring, a nutritional carrier, a nutraceutical, a material to enhance adhesion of the algae to at least one tooth of an animal, an antimicrobial (e.g., an antimicrobial peptide or an antibiotic), a plaque-reducing agent, and a calculus-reducing agent.

In still other illustrative embodiments, the algae can be selected from the group consisting of live algae, dead algae, and combinations thereof, or the algae can be of the species Chlamydomonas reinhardtii.

In yet another method embodiment, a method is provided for reducing plaque on at least one tooth of an animal. The method comprises the step of causing the at least one tooth of the animal to be contacted with a composition comprising algae wherein the composition comprising the algae reduces the plaque on the at least one tooth of the animal and wherein the composition comprising the algae acts directly on the at least one tooth.

In the method embodiment described in the preceding paragraph, the algae can be selected from the group consisting of green algae, brown algae, red algae, and diatoms. In additional embodiments the algae can be in the form of a paste, a gel, a liquid (e.g., for addition to the drinking water of the animal), a freeze-dried composition, a powder, a component of an animal treat, a nugget, a dressing for an animal food, an additive for water, a component of a chew product, or a pellet. In another illustrative embodiment, the algae can be freeze-dried and can be capable of being reconstituted.

In illustrative aspects of this method embodiment, the algae can be genetically modified (e.g., to express an antimicrobial peptide). In yet another embodiment of this method, the algae composition can further comprise one or more of a preservative, an inert carrier (e.g., selected from the group consisting of a paste and a gel), a flavoring, a nutritional carrier, a nutraceutical, a material to enhance adhesion of the algae to at least one tooth of an animal, an antimicrobial (e.g., an antimicrobial peptide or an antibiotic), a plaque-reducing agent, and a calculus-reducing agent.

In still other illustrative embodiments of the above-described method embodiment, the algae can be selected from the group consisting of live algae, dead algae, and combinations thereof, or the algae can be of the species Chlamydomonas reinhardtii. In other embodiments, the animal treated with the algae composition can be, for example, a cat or a dog. In another illustrative aspect, the algae can adhere to the at least one tooth for a prolonged period of time and the plaque can be present on more than one tooth.

In yet another illustrative aspect, a kit is provided. The kit comprises a green algae composition wherein the green algae composition is adapted for contact with at least one tooth of an animal. In this embodiment, the kit further comprises an applicator for rubbing the green algae composition on the at least one tooth of the animal. In another embodiment, the kit comprises a syringe for applying the algae composition to the teeth. In any of these embodiments, the kit can comprise instructions for use.

In this kit embodiment, the algae can be in the form of a paste, a gel, a liquid (e.g., for addition to the drinking water of the animal), a powder, a freeze-dried composition, or an additive for water. In another illustrative kit embodiment, the algae can be freeze-dried and can be capable of being reconstituted.

In illustrative aspects of the above-described kit embodiment, the algae can be genetically modified (e.g., to express an antimicrobial peptide). In yet another kit embodiment, the algae composition can further comprise one or more of a preservative, an inert carrier (e.g., selected from the group consisting of a paste and a gel), a flavoring, a nutritional carrier, a nutraceutical, a material to enhance adhesion of the algae to at least one tooth of an animal, an antimicrobial (e.g., an antimicrobial peptide or an antibiotic), a plaque-reducing agent, and a calculus-reducing agent.

In still other illustrative kit embodiments, the algae can be selected from the group consisting of live algae, dead algae, and combinations thereof, or the algae can be of the species Chlamydomonas reinhardtii. In another illustrative kit embodiment, the algae can adhere to the at least one tooth for a prolonged period of time and the algae composition can cause plaque reduction on at least one tooth of an animal.

In yet another embodiment, an article of manufacture is provided. The article of manufacture comprises a commercial package containing a composition comprising green algae adapted for contact with at least one tooth of an animal. In this embodiment, the article of manufacture can be air-tight and can also be leak-resistant.

In this article of manufacture embodiment, the algae can be in the form of a paste, a gel, a liquid (e.g., for addition to the drinking water of the animal), a powder, a freeze-dried composition, a component of an animal treat, a nugget, a dressing for an animal food, an additive for water, a component of a chew product, or a pellet. In another illustrative embodiment, the algae can be freeze-dried and can be capable of being reconstituted.

In illustrative aspects of the above-described article of manufacture embodiment, the algae can be genetically modified (e.g., to express an antimicrobial peptide). In yet another article of manufacture embodiment, the algae composition can further comprise one or more of a preservative, an inert carrier (e.g., selected from the group consisting of a paste and a gel), a flavoring, a nutritional carrier, a nutraceutical, a material to enhance adhesion of the algae to at least one tooth of an animal, an antimicrobial (e.g., an antimicrobial peptide or an antibiotic), a plaque-reducing agent, and a calculus-reducing agent.

In still other illustrative article of manufacture embodiments, the algae can be selected from the group consisting of live algae, dead algae, and combinations thereof, or the algae can be of the species Chlamydomonas reinhardtii. In other article of manufacture embodiments, the animal treated with the algae composition can be, for example, a cat or a dog. In another illustrative aspect, the algae can adhere to the at least one tooth for a prolonged period of time and the algae composition can cause plaque reduction.

For all of the above-described embodiments, any applicable combination of embodiments is also contemplated (e.g., an algae composition could further comprise an inert carrier, a flavoring, and a nutritional carrier or the algae could be genetically modified and the algae composition could further comprise an inert carrier, a flavoring, and a nutritional carrier). Any applicable combination of the above-described embodiments is considered to be in accordance with the invention.

In another embodiment, a composition comprising algae for reducing plaque on at least one tooth of an animal is provided.

In yet another embodiment, a composition comprising algae is provided wherein the algae composition is adapted for contact with at least one tooth of an animal. In this embodiment, 1) the algae composition can be selected from green algae, red algae, and diatoms, 2) the algae can be green algae, 3) the algae can be in the form of a paste, gel, liquid, nugget, powder, pellet, dressing for animal food or an additive for drinking water or are a component of an oral or digestible treat or chew product, 4) the algae can be freeze-dried and are capable of being reconstituted, 5) the algae can be genetically modified, 6) the algae can be genetically modified to express an antimicrobial peptide, 7) the algae composition can further comprises a preservative, flavoring, inert carrier or nutritional carrier, 8) the inert carrier can be selected from a paste and a gel, 9) the algae composition can further comprise a material to provide adhesion of the algae to the at least one tooth, 10) the algae composition can further comprise an antimicrobial peptide or other antimicrobial, an antibiotic, an additional plaque-reducing agent or a calculus-reducing agent, 11) the algae can be selected from live algae, dead algae, and combinations thereof, 12) the algae can be from the species Chlamydomonas reinhardtii, 13) the animal can be a dog or a cat, or 14) the algae can adhere to the at least one tooth for a prolonged period of time. Any combination of the embodiment of paragraph [0025] with 1-14, or any combination thereof, is contemplated.

In still another embodiment, a kit is provided comprising an algae composition wherein the algae composition is adapted for contact with at least one tooth of an animal. In this embodiment, 1) the algae can be green algae, 2) the kit can further comprise an applicator for rubbing the green algae composition on the at least one tooth of the animal, or 3) the kit can further comprise a syringe. Any combination of the embodiment of paragraph [0026] with 1-3, or any combination thereof, is contemplated.

In a further embodiment, the use of a composition comprising algae in the manufacture of a medicament adapted for contact with at least one tooth of an animal is provided. In this embodiment, 1) the algae composition can be selected from green algae, red algae, and diatoms, 2) the algae can be green algae, 3) the algae or medicament can be in the form of a paste, gel, liquid, nugget, powder, pellet, dressing for animal food or an additive for drinking water or are a component of an oral or digestible treat or chew product, 4) the algae can be freeze-dried and are capable of being reconstituted, 5) the algae can be genetically modified, 6) the algae can be genetically modified to express an antimicrobial peptide, 7) the algae composition can further comprise a preservative, flavoring, inert carrier or nutritional carrier, 8) the inert carrier can be selected from a paste and a gel, 9) the algae composition can further comprise a material to provide adhesion of the algae to the at least one tooth, 10) the algae composition can further comprise an antimicrobial peptide or other antimicrobial, an antibiotic, an additional plaque-reducing agent or a calculus-reducing agent, 11) the algae can be selected from live algae, dead algae, and combinations thereof, 12) the algae can be from the species Chlamydomonas reinhardtii, 13) the animal can be a dog or a cat, or 14) the algae can adhere to the at least one tooth for a prolonged period of time. Any combination of the embodiment of paragraph [0027] with 1-14, or any combination thereof, is contemplated.

In any of the above-described embodiments, plaque reduction can occur by about 24 hours after treatment with the algae composition.

BRIEF DESCRIPTION OF THE DRAWINGS

The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawings will be provided by the Office upon request and payment of the necessary fee.

FIG. 1 shows cells of CC-1284 remaining on a molar following coating the molar with an algal paste and successive rinses with deionized water. Panels A-F represent the first through sixth rinses, respectively.

FIG. 2 shows cells of CC-1952 remaining on a molar following coating the molar with an algal paste and successive rinses with deionized water. Panels A-F represent the first through sixth rinses, respectively.

FIG. 3 shows the quantitative light-induced fluorescence imaging of molars coated with an algal paste from CC-1284 (Panels A and B) and CC-1952 (Panels C and D) before (Panels A and C) and after (Panels B and D) rinsing six times with deionized water.

DETAILED DESCRIPTION OF THE INVENTION

While the invention is susceptible to various modifications and alternative forms, illustrative embodiments are described herein. It should be understood, however, that there is no intent to limit the invention to the particular forms described, but on the contrary, all modifications, equivalents, and alternatives falling within the spirit and scope of the invention are covered.

As used herein, “biofilm” means a dental biofilm.

As used herein, “calculus” means plaque that has partially or completely calcified.

As used herein, “at least one tooth” means one tooth or more than one tooth of an animal.

As used herein, “whole algae” means algae that have not been extracted (e.g., using a standard cellular extraction method known in the art).

As used herein, the terms “reducing,” “reduce,” “reduces,” and “reduction” in reference to biofilm, plaque, or calculus mean that a lower amount of biofilm, plaque, or calculus, or a combination thereof, is found on at least one tooth of an animal after treatment with the compositions described herein, or that biofilm, plaque, or calculus, or a combination thereof, is completely removed from at least one tooth of an animal after treatment with the compositions described herein, or that biofilm, plaque, or calculus, or a combination thereof, is prevented from forming on at least one tooth of an animal after treatment with the compositions described herein.

As used herein, “green algae” means microalgae from the group Chlorophyta.

As used herein, “brown algae” means microalgae from the group Phaeophyta.

As used herein, “red algae” means microalgae from the group Rhodophyta.

As used herein, “diatoms” means microalgae from the group Bacillariophyta.

As used herein, “algae” means microalgae.

In various embodiments of the methods and compositions described herein, the animal treated with the algae compositions according to the methods described herein can be, for example, a domestic animal, such as a dog, a cat, or a ferret, a wild animal in captivity such as a bear, a panda, a lion, a tiger, a leopard, an elephant, a zebra, a giraffe, a monkey, a chimpanzee, or a gorilla, an equine species (e.g., a race horse), or a human. It should be understood, however, that this list of animals that can be treated using the methods and compositions described herein is non-limiting, and any type of animal in need of treatment with the methods and dental compositions described in this application can be treated.

The invention relates to a dental composition, kits containing the dental composition, articles of manufacture comprising the dental composition, and methods of use of the dental composition. More specifically, the invention relates to a dental composition for an animal wherein the dental composition comprises algae. The invention also relates to methods of use of the dental composition comprising algae, including methods of reduction of plaque on at least one tooth of an animal. The algae for use in these compositions, kits, articles of manufacture, and methods can be green algae, brown algae, red algae, or diatoms, but are typically green algae.

In one embodiment of the invention, a method is provided for reducing plaque on at least one tooth of an animal. The method comprises the step of causing the at least one tooth of the animal to be contacted with a composition comprising algae wherein the composition comprising the algae reduces the plaque on the at least one tooth of the animal and wherein the composition comprising the algae acts directly on the at least one tooth.

In another embodiment of the invention, a method is provided for reducing plaque on at least one tooth of an animal. The method comprises the step of causing the at least one tooth of the animal to be contacted with a composition comprising green algae wherein the composition comprising the green algae reduces the plaque on the at least one tooth of the animal.

In yet another embodiment of the invention, a composition comprising green algae is provided, wherein the green algae composition is adapted for contact with at least one tooth of an animal.

In another illustrative aspect of the invention, a kit is provided. The kit comprises a green algae composition wherein the green algae composition is adapted for contact with at least one tooth of an animal. In this embodiment, the kit can further comprise an applicator for rubbing the green algae composition on at least one tooth of the animal. In another embodiment, the kit can comprise a syringe for application of the algae composition to at least one tooth of the animal. In yet another embodiment, the kit can contain instructions for use. Other suitable kit components include algal rinse compositions, brushes, algal paste compositions, a powdered algae composition for dispersion in the drinking water of the animal, freeze-dried algae, chew treats, and the like. The kit can also contain an algae composition that comprises green algae, brown algae, red algae, diatoms, or a combination thereof.

In yet another embodiment of the invention, an article of manufacture is provided. The article of manufacture comprises a commercial package containing a composition comprising green algae adapted for contact with at least one tooth of an animal. In one illustrative embodiment, the article of manufacture can be packaged in an air-tight container. In another illustrative aspect, the article of manufacture can be packaged in a container that is leak-resistant.

For each of the above-described composition, kit, article of manufacture, and method embodiments, various modifications and alternative forms, and illustrative embodiments and aspects are described below. All of the illustrative embodiments, modifications, and alternative forms described below may be applied to the embodiments described in the preceding paragraphs [0046] to [0051] of this Detailed Description section.

In some of the above-described embodiments, the algae are green algae. In accordance with the invention, “green algae” means microalgae from the group Chlorophyta. In other embodiments, the algae can be any type of microalgae including, for example, green algae, brown algae, red algae, or diatoms, or combinations thereof, as long as the algae are microalgae. In accordance with the invention, “brown algae” means microalgae from the group Phaeophyta. In accordance with the invention, “red algae” means microalgae from the group Rhodophyta. In accordance with the invention, “diatoms” means microalgae from the group Bacillariophyta.

In various embodiments, whole algae (e.g., whole algae, either ground algae or algae that has not been ground) can be used in the algal paste, gel, liquid, powder, freeze-dried composition, and other applicable forms that are used in accordance with the invention. In an alternate embodiment, algae extracts, including purified components of the algae, can be used. In other illustrative embodiments, the algae can be selected from the group consisting of live algae, dead algae, and combinations thereof.

Exemplary green algae that can be used include Chlamydomonas species, (e.g., Chlamydomonas reinhardtii), Chlorella species, Volvox species, Dunaliella species, Nannochloris species, Oedogonium species, and some marine macrophytes.

Chlamydomonas reinhardtii is an exemplary green algae that can be used in the methods and compositions described herein. Chlamydomonas reinhardtii grows rapidly and is easy and inexpensive to grow in culture. Exemplary Chlamydomonas strains include CC-425, CC-741, CC-744, CC-1284, CC-1952, CC-2137, CC-2277, CC-2519 CC-2677. These strains are available from the Chlamydomonas Center, University of Minnesota (Minneapolis, Minn.). Exemplary website addresses include http://www.chlamy.org/chlamydb.html or http://www.chlamy.org/strains.html or http://www.chlamy.org/info.html. Chlamydomonas strains, or other green algae strains, are also available from the ATCC (American Type Culture Collection, P.O. Box 1549, Manassas, Va. 20108). An exemplary website address is http://www.atcc.org/ATCCAdvancedCatalogSearch/tabid/112/Default.aspx. Any suitable Chlamydomonas strain that can be obtained from the Chlamydomonas Center or the ATCC, or that is known to the skilled artisan can be used.

In illustrative embodiments, the algal cells can be cultured using a variety of techniques known in the art. Typically, algal cultures are supplemented with a carbon source (e.g., glucose or acetate), and the algal cells can be cultured to achieve a desired density. Briefly, standard sterile techniques known to those skilled in the art can be used. In one embodiment, algal cells can be inoculated into standard algal cell culture medium using a laminar flow hood to maintain sterile conditions and the algae can then be cultured with aeration at about 23° C. using 18 hour light/6 hour dark cycles. In one illustrative embodiment, progression from small cultures (e.g., 30 ml) to larger cultures (e.g., 200 ml) to large flasks (e.g., 2 liters) is used. The algal cultures are typically stirred to maintain the cells in suspension. In one embodiment, if the pH of the medium increases to above about 9, for example, the culture medium can be bubbled with CO₂ to reduce the pH to about 7, or an alkaline buffering compound, such as NaHCO₃, can be added. When a desired algal cell density is achieved, an algal cell pellet (e.g., a paste) can be collected by centrifugation, and the supernatant discarded.

In illustrative embodiments, whole algae (e.g., either algae that has been disrupted (e.g., by grinding the algae) or algae that is not disrupted) can be used in the algae paste, gel, liquid, powder, freeze-dried composition, and other applicable forms described herein. The algae can, for example, be collected from culture medium by pelleting the algae by centrifugation and the algal pellet can be used in the compositions described herein. In alternate embodiments, an algal component (e.g., a purified component) or algal components (e.g., a partially purified extract) can be used.

In embodiments where it is desirable to extract and purify a component(s) of the algae for use in the methods and compositions described herein, the algal component(s) (e.g., a protein) can be purified from the algal cell pellet after extraction of the algal cells. In one embodiment, freeze-dried algae can be extracted with a suitable solvent such as ethanol, methanol, isopropanol, or dichloromethane. In various embodiments, conventional purification techniques can be used. For purification of a component(s) from an algal cell extract, the extract can, for example, be subjected to ammonium sulfate precipitation followed by DEAE-Sepharose column chromatography. Other conventional techniques known to those skilled in the art can be used for purification such as gel filtration, ion exchange chromatography, DEAE-Sepharose column chromatography, affinity chromatography (e.g., the FLAG-tagged system described in WO 2008/021223, incorporated herein by reference), solvent-solvent extraction, ultrafiltration, tangential flow filtration, FPLC and HPLC. The purified algal component(s) can be concentrated, if desired, by such techniques as, for example, ultrafiltration and tangential flow filtration.

In one embodiment where it is desirable to extract and purify a component(s) of the algae for use in the methods and compositions described herein, the algal cells can be lysed, for example, by sonication, heat, or chemical treatment, and the lysate extracted with a suitable solvent such as ethanol, methanol, isopropanol, or dichloromethane, and then the lysate can be centrifuged to remove cell debris. The supernatant can then be subjected to fractionation techniques, as required, such as ammonium sulfate precipitation, dialysis, gel filtration, ion exchange chromatography, DEAE-Sepharose column chromatography, affinity chromatography, solvent-solvent extraction, ultrafiltration, FPLC, and HPLC to purify the desired algal component(s).

In this embodiment, the algal component(s) can be purified in a substantially pure form. Exemplary substantially pure compositions can be about 40% pure, about 50% pure, about 60% pure, about 70-80% pure, about 90% pure, about 95% pure, or about 98% pure. It should be understood that the purification methods described above for purification of desired algal component(s) are nonlimiting and any purification techniques known to those skilled in the art can be used if a substantially pure algal component(s) is desired, and such techniques are required to obtain the substantially pure component(s).

For the embodiments described herein where the algae are genetically modified, exogenous nucleotides (e.g., DNA) can be introduced into the nuclear, chloroplast, or mitochondrial genome of the algae. Nuclear transformation of the algae can be performed, for example, by electroporation essentially as described in Shimogawara, et al., Genetics Vol. 148, 1821-1828, incorporated herein by reference. In another illustrative embodiment, nuclear, chloroplast, or mitochondrial transformation can be achieved using a transgene flanked by homologous nuclear, chloroplast, or mitochondrial targeting sequences that facilitate integration of the transgene into the desired site. See, for example, the chloroplast transformation vector described in WO 2008/021223, incorporated herein by reference. In other embodiments, other standard transformation methods known to the skilled artisan can be used including calcium phosphate precipitation, DEAE-dextran transformation techniques, and biolistics. In some embodiments, the molecule expressed (e.g., a peptide, a polypeptide, or a protein) can be expressed at high efficiency (e.g., as described in WO 2008/021223, incorporated herein by reference).

In various illustrative embodiments, the algae can be genetically modified to express a plaque-reducing agent, a calculus-reducing agent, an antimicrobial (e.g., an antimicrobial peptide), and the like. Antimicrobial peptides can include, for example, peptides that inhibit interaction or binding of microbes to components of biofilm, plaque, or calculus, peptides that interfere with the metabolism of microbes, peptides that damage the cell walls of microbes, and the like. Methods of identifying antimicrobial peptides are known in the art and are described in U.S. Pat. Nos. 7,465,784 and 7,393,999, incorporated herein by reference.

In one embodiment, auxotrophic mutants that can be used (i.e., mutants that differ from the wild-type in requiring one or more nutritional supplements for growth) are readily available at the Chlamydomonas Center, University of Minnesota (Minneapolis, Minn.; e.g., http://www.chlamy.org/info.html). Such mutants can be genetically complemented by transforming the mutant algae with nucleotides (e.g., exogenous DNA), which facilitates selection of transformed algae containing a desired transgene. This selection method avoids the need for the use of an antibiotic-based selection method.

In one embodiment, the genetically modified algae that express a desired protein, polypeptide, peptide, etc. are further genetically modified such that they will not proliferate in the environment in general, but rather will proliferate only in specific controlled environments (i.e., such strains will not grow or transfer their genes in the wild). In accordance with this invention, such algae are said to be “disabled.” Use of such disabled algae strains inhibits or limits spread of the genetically modified algae into the environment.

In one embodiment, disabled strains of algae can be constructed by incorporating a genetic mutation that precludes growth and/or mating outside of a specific controlled environment. For example, the genetically modified algae may be engineered to contain mutations that prevent photosynthesis, and such strains are unlikely to survive in the wild because they cannot produce the energy or reduced carbon necessary to sustain life. An exemplary mutation preventing photosynthesis is a mutation in genes comprising the psbD/psaC operon of C. reinhardtii, which is part of the chloroplast genome of C. reinhardtii. In other embodiments, mutations useful in constructing disabled algal strains are mutations in genes that result in strains that cannot grow in the absence of specific metabolites. These mutant strains are said to be “auxotrophic” for the particular metabolite (e.g, amino acids, vitamins, etc.). In various embodiments, useful mutations require cells to be grown in the presence of arginine, thiamine, or nicotinamide. In yet another embodiment, multiple mutations of the type described above, for example, are combined into a single strain of algae. Combinations of these mutations in a single strain (also called “stacking” of mutations) result in disabled strains that are particularly nonfunctional in growth and mating, and in the ability to grow and transfer their genes in the wild.

In another embodiment, a disabled algal strain takes advantage of mating events. For example, in C. reinhardtii, when haploid (+) and (−) cells mate to form a diploid cell, only the chloroplast genomes from the (+) mating type organism survive. The chloroplast genomes of the (−) mating type cells are degraded during mating. Accordingly, C. reinhardtii strains in which the transgene encoding the expressed molecule is located in the chloroplast genome of a (−) cell are advantageous when control of proliferation of transgenic algae is desired. In yet another embodiment, the algal strain can be disabled by mutations in the genes encoding flagella. For example, in C. reinhardtii, flagella are necessary to hold (−) and (+) cells together during mating. Accordingly, transgene-containing cells with mutations in genes encoding flagella will be unable to transmit the transgene through mating.

In various embodiments of the methods and compositions described herein, the algae can be in the form of a paste, a gel, a liquid (e.g., for addition to the drinking water of an animal), a powder, or a freeze-dried composition (e.g., a composition that is capable of being reconstituted). In one embodiment, the algae can be dried for storage and/or preservation.

In various illustrative aspects, algal pastes can be made by harvesting algal cultures by continuous centrifugation in a batch-centrifuge, where the algal pellet is collected and yields an algal paste. In an alternate embodiment, algae can be harvested by gravitational sedimentation (e.g., in a conical tank). The algal sediment can then be collected and centrifuged to yield the algal paste. In yet another embodiment, the algae may be flocculated from the culture medium by the addition of certain salts, such as ferric chloride, aluminum chloride or aluminum sulfate. The cells that settle out after flocculation may be harvested by centrifugation to generate the algal paste. In yet another embodiment, algae can be concentrated by cross-flow filtration, and then centrifuged to form an algal paste. Other methods for forming an algal paste for use in the methods and compositions described herein are known to those skilled in the art.

In another embodiment, an algal powder can be made by, for example, freeze-drying an algal paste, milling the freeze-dried algae, or grinding the algae in a Waring blender, for example, and then sieving the milled or ground algae composition to form a powder. In one embodiment, the powdered algae can be used directly in the algal compositions described herein for use in treating the teeth of animals. In another embodiment, the powdered algae can be freeze-dried for storage, and reconstituted for use in the algae compositions described herein. In another embodiment, various types of algae forms (e.g. a paste, a powder, a freeze-dried (according to protocols known in the art) algae composition, an algae composition dried in a commercial drier, etc.) can be reconstituted in, for example, a buffer solution or in water to form the liquid algae composition which is used, for example, as an additive for the drinking water of an animal. Algal gel compositions can be made according to procedures well-known to those skilled in the art.

In the above described embodiments of the algal form, the animal can be treated with the algae composition where the algae composition is a component of an animal treat, is in the form of a dressing for animal food, is in the form of a nugget, a pellet, is in the form of an additive for water, or is a component of a chew product (e.g., either an oral or digestible chew product). Any suitable regimen for treatment of the animal with the algae compositions described herein can be used. A person skilled in the art would be readily able to determine a dosing regimen depending on the type of formulation used. Exemplary treatment regimens include application of the algae composition to the teeth of the animal one or more times daily (e.g., one, two, or three times) on weekdays, and one or more times daily on weekends (e.g., one, two, or three times). In another embodiment, a daily regimen is used with application of the algae composition to the teeth of the animal once daily. Further, a staggered regimen, for example, one to three days per week can be used as an alternative to daily treatment, and for the purpose of defining this invention such an intermittent or staggered daily regimen is considered to be within the scope of this invention.

In any of the embodiments described in this application the algae composition can comprise about 90% by weight of algae, about 1% to about 20% by weight of algae, about 15% to about 40% by weight of algae, about 30% to about 60% by weight of algae, about 50% to about 80% by weight of algae, or about 60% to about 100% by weight of algae. In these embodiments, the algae can be whole algae or an extract or purified component of the algae.

In various embodiments of the methods and compositions described herein, the algae compositions can further comprise one or more of a preservative, a flavoring, an inert carrier (e.g., which can be in the form of a paste or a gel), an antimicrobial peptide, an antimicrobial (e.g., an antibiotic), a plaque-reducing agent, a calculus-reducing agent, a nutritional carrier, a nutraceutical, or other suitable additives.

In another embodiment, preservatives can be added to the algae compositions described herein. Exemplary preservatives include, but are not limited to, Thimersol, benzyl alcohol, methylparaben, propylparaben, benzoic acid, sodium benzoate, and potassium sorbate.

In an additional embodiment a flavoring may be added to the algae composition described herein. Exemplary flavorings include garlic, wood smoke, meat extracts and other meat flavorings, fish extracts and other fish flavorings (e.g., Tuna fish flavoring), fermentation residues, and any combination thereof. In embodiments where the algae composition is for treatment of the teeth of humans, flavorings can include apple, orange, cherry, vanilla, watermelon, bubble gum, apricot, grape, currant, and lemon flavorings, and any combination thereof. In still another embodiment the flavoring may be a sweetening agent, such as saccharin, dextrose, levulose, aspartame, D-tryptophan, dihydrochalcones, sodium cyclamate, sucrose, fructose, glucose, and any combination thereof.

In another illustrative aspect, an oral pharmaceutically acceptable inert carrier can be added to the algae compositions described herein. The inert carrier can be, for example, in the form of a gel, a paste, a powder, or a liquid. Exemplary inert carriers include, but are not limited to, lactose, starch (pharmaceutical grade), dextrin, dicalcium phosphate, calcium sulfate, kaolin, and mannitol.

In yet another embodiment, an antimicrobial peptide can be either expressed in the genetically modified algae that are used in the algae compositions described herein, or can be an additive to the algae compositions described herein, or a combination thereof. Suitable antimicrobial peptides include peptides that inhibit interaction or binding of microbes to components of biofilm, plaque, or calculus, peptides that interfere with the metabolism of microbes, and peptides that damage the cell walls of microbes, and the like. Exemplary methods of identifying antimicrobial peptides are known in the art, and are described in U.S. Pat. Nos. 7,465,784 and 7,393,999, incorporated herein by reference.

In still another embodiment, antimicrobial agents can be included in the algae compositions described herein. Such agents may include, but are not limited to 5-chloro-2-(2,4-dichlorophenoxy)-phenol, 8-hydroxyquinoline, copper II compounds, phthalic acid, chlorhexidine, alexidine, hexetidine, sanguinarine, benzalkonium chloride, salicylanilide, domiphen bromide, cetylpyridinium chloride, tetradecylpyridinium chloride, N-tetradecyl-4-ethylpyridinium chloride, octenidine, iodine, sulfonamides, bisbiguanides, phenolics, delmopinol, octapinol, and other piperidino derivatives, and nicin preparations, any suitable antibiotics such as augmentin, amoxicillin, tetracycline, doxycycline, minocycline, metronidazole, neomycin, kanamycin, and clindamycin, and any salts of any of these compounds where applicable, and any combinations of these compounds. In another embodiment, antiviral compounds can be included, alone or in combination with any of the above-described antimicrobials. Exemplary anti-viral compounds include cytosine derivatives, purine anaglogues, pyrimidine bases, amantadines, ribavirin, zanamivir, acyclovir, and the like. In yet another embodiment, anti-fungal compounds can be included, alone or in combination with any of the above-described antimicrobials. Anti-fungals agents that are suitable for use in the algae compositions described herein include, but are not limited to, nystatin, miconazole, econazole nitrate, clotrimazole, and flucytosine.

In yet another embodiment, a plaque-reducing agent may be added such as zinc citrate, sanguinarine, chlorhexidine, baking soda, hydrogen peroxide, stannous salts, copper salts, strontium salts, or magnesium salts, and any combination thereof. Additional exemplary plaque-reducing agents include, for example, fluoride anions. In one embodiment a fluoride anion may be added such as sodium fluoride, stannous fluoride, potassium fluoride, ammonium fluoride, zinc fluoride, germanium fluoride, palladium fluoride, titanium fluoride, sodium fluorozirconate, potassium fluorozirconate, stannous fluorozirconate, stannous fluoroborate, stannous fluorosulfate, sodium fluorosulfate, potassium fluorosulfate, calcium fluorosulfate, mono fluoro phosphate, and mixtures thereof. Exemplary fluoride ion-yielding materials can be found in U.S. Pat. No. 3,535,421 and U.S. Pat. No. 3,678,154, each incorporated herein by reference.

In another illustrative aspect, a calculus-reducing agent may be added such as polyphosphates (including pyrophosphates), polyamino propane sulfonic acid, polyolefin sulfonates, polyvinyl phosphates, polyolefin phosphates, diphosphonates, phosphonoalkane carboxylic acid, polyphosphonates, polyvinyl phosphonates, polyolefin phosphonates, carboxylic acids (including malic, citric and fumaric acids), sodium hexamethaphosphate, and salts of any of these compounds, and any combination thereof.

In yet another illustrative embodiment, a nutritional carrier or supplement may be added to the algae compositions described herein. Exemplary nutritional carriers include minerals, vitamins, oral nutritional supplements, enteral nutritional supplements, and any combination thereof. Minerals that can be used include, but are not limited to, calcium, phosphorus, zinc, manganese, potassium, and any combination thereof. Suitable vitamins include, but are not limited to, vitamins C and D, thiamine, riboflavin, calcium pantothenate, niacin, folic acid, nicotinamide, pyridoxine, cyanocobalamin, para-aminobenzoic acid, bioflavonoids, and any combination thereof. Amino acids can also be added and include, but are not limited to 1-tryptophan, 1-lysine, methionine, threonine, levocarnitine, or 1-carnitine, and any combination thereof. Additional exemplary nutritional supplements include fish oils, in particular fish oils containing large amounts of omega-3 polyunsaturated fatty acids, such as eicosapentaenoic acid and docosahexaenoic acid. Enteral nutritional supplements include, but are not limited to, protein products, glucose polymers, corn oil, and safflower oil. In yet another embodiment, any of these nutritional supplements can be added in any combination.

In another illustrative embodiment, a nutraceutical can be added to the algae compositions described herein. A person skilled in the art would readily be able to determine the type(s) of anti-inflammatory agents useful for the particular animal. Suitable nutraceuticals include anti-inflammatory agents. Exemplary anti-inflammatory agents include non-steroidal anti-inflammatory agents (NSAIDs) including salicylates, propoionic acids, and fenamates, including but not limited to ibuprofen, indomethacin, diclofenac, fenoprofen, piroxicam, nabumetone, aspirin, diflunisal, meclofenamate, mefenamic acid, oxyphenbutazone, phenylbutazone, and acetaminophen. Exemplary steroidal anti-inflammatory agents include corticosteroids, such as hydrocortisone.

In another illustrative aspect, the algae compositions described herein can further comprise such additives as pharmaceutically acceptable diluents, solubilizing agents, a breath enhancing agent, an abrasive, a polish, a thickening agent, a binding agent, and an antioxidant, or combinations thereof. In various embodiments the algae compositions can include pharmaceutically acceptable diluents (e.g., liquid alcohols, glycols (e.g., polyethylene glycols), glucose solutions (e.g., 5%), esters, amides, sterile water, buffers (including phosphate or acetate buffers, isotonic saline, and Tris buffers)).

In another embodiment, the solubilizing agents can be, for example, propylene glycol, dipropylene glycol, hexylene glycol, methyl cellosolve, ethyl cellosolve, amyl acetate, ethyl acetate, benzyl benzoate, Tween 80, or Polysorbate 80.

In another embodiment a breath enhancing agent may be added to the algae compositions described herein such as oil of peppermint, oil of wintergreen, oil of spearmint, oil of clove, oil of sassafras, and mixtures thereof.

In various aspects, antioxidants can also be added. Exemplary antioxidants include beta-carotene, vitamin E, vitamin C, vitamin A, tocopherol, butylated hydroxytoluene, butylated hydroxyanisole, tertiary-butylhydroquinone, propyl gallate, ascorbic acid, sodium metabisulfite, uric acid, carotenoids, flavonoids, melatonin, and ethoxyquin.

In any of the above-described embodiments, the algae composition can further comprise a material to enhance adhesion of the algae to at least one tooth of an animal, and the algae can adhere to at least one tooth of an animal for a prolonged period of time, either due to the presence of an agent that enhances adhesion of the algae to the teeth, or due to the adherence characteristics of the algae. Exemplary materials that enhance adhesion of algae to at least one tooth of the animal include carbohydrates and/or carbohydrate-containing materials and proteins known in the art to enhance adherence of microorganisms to a substrate.

The following examples illustrate specific embodiments in further detail. These examples are provided for illustrative purposes only and should not be construed as limiting the invention or the inventive concept in any way.

EXAMPLES Example 1 Culture and Preparation of Algae Composition

The algal cells can be cultured using a variety of techniques known in the art. Typically, algal cultures are supplemented with a carbon source (e.g., glucose or acetate), and the algal cells can be cultured to achieve a desired density. Briefly, standard sterile techniques known to those skilled in the art can be used. The algal cells can be inoculated into standard algal cell culture medium using a laminar flow hood to maintain sterile conditions and the algae can then be cultured with aeration at about 23° C. using 18 hour light/6 hour dark cycles. Progression from small cultures (e.g., 30 ml) to larger cultures (e.g., 200 ml) to large flasks (e.g., 2 liters) can be used. The algal cultures are typically stirred to maintain the cells in suspension. If the pH of the medium increases to above about 9, the culture medium can be bubbled with CO₂ to reduce the pH to about 7, or an alkaline buffering compound, such as NaHCO₃, can be added. When a desired algal cell density is achieved, an algal cell pellet can be collected by centrifugation, and the supernatant discarded.

Example 2 Plaque Reduction in Cats

Experiments were conducted with C. reinhardtii to determine if the oral delivery of the algae as a paste to the surface of the teeth of cats is an effective means to reduce plaque accumulation. Algal strains CC-741 and CC-2677 were grown for 1 week in modified Tapp media (Harris, 1989) in 20 liter carboys and harvested using a TZ28 Sorval rotor at 16,000 RPM at 4° C. Approximately 200 liters (10 carboys) were harvested for each strain. The algal paste was collected from the rotor and stored at 4° C. for approximately 1 week. The algal paste was packed into a 10 ml syringe and 1 cc of the paste was delivered to the teeth of 5 cats. Following delivery of the paste, the paste was dispersed on the surface of the teeth by manually massaging the animals' cheeks.

The results from the experiments show that plaque accumulation on the teeth of animals treated with the algal paste of strain CC-741 was less than plaque accumulation on the teeth of the control group. Four of the five animals treated with the algal paste show a reduction in the amount of plaque by 24 hours after treatment. In contrast, 3 of the 5 control animals show an increase in plaque accumulation during the same time period. One animal (Laurel) in the control group appears to deviate substantially from the response of the animals, showing a precipitous decrease in plaque accumulation. The data from the trial is provided in Tables 1, 2, 3, and 4. The results show a 24% reduction in plaque for animals treated with C. reinhardtii strain CC-741 (Table 1; Group A) versus controls (Table 2; Group B). The results for C. reinhardtii strain CC-2677 are shown in Tables 3 and 4. C. reinhardtii strain CC-741 is a walled algal strain and C. reinhardtii strain CC-2677 lacks cell walls.

TABLE 1 Plaque evaluation following treatment of feline teeth with C. reinhardtii strain CC-741 (Group A) Cat Baseline 24 hour Grace 6.33 5.17 Magpie 7.17 5.67 Aruba 7.00 5.00 Lilac 3.50 3.50 Shirley 5.83 3.33 Mean 5.97 4.53 S.D. 1.48 1.05 % Change 24%

TABLE 2 Plaque evaluation following treatment of feline teeth with deionized water (Group B) Cat Baseline 24 hour Lily 10.00 10.33 Laurel 8.67 4.5 Kitt 3.33 4.16 Bora Bora 8.33 8.67 Audrey 4.50 4.33 Mean 6.97 6.40 S.D. 2.88 2.89 % Change 8%

TABLE 3 Plaque evaluation following treatment of feline teeth with C. reinhardtii strain CC-2677 (Group A) Cat Baseline 24 hour Sage 11.8 8.67 Robin 7 7.5 Maui 6.33 8.67 Bora Bora 6.17 9.5 Mean 7.83 8.59 S.D. 2.67 0.82 % Change 10%

TABLE 4 Plaque evaluation following treatment of feline teeth with deionized water (Group B) Cat Baseline 24 hour Figi 2.5 2.67 Judy 8.5 9 Chickadee 7.5 4.8 Finch 7 5.67 Mean 6.38 5.54 S.D. 2.66 2.63 % Change 13%

Example 3 Plaque Reduction in Dogs

Thirty healthy, purpose-bred beagle dogs 1 year of age or older, with normal dental occlusion, received a full dental scaling and polishing of their teeth under general anesthesia (Day-7) (7 days before the start of the testing). On Day 0 and Day 14 each animal was placed under short acting anesthesia to evaluate the plaque indices using a modified Quigley and Hein (1962) (Turesky, 1970) plaque index after the application of a disclosing agent to the teeth followed by rinsing to remove residual excess. The teeth were visually halved horizontally into gingival and occlusive halves that were each given a score for the percentage of coronal surface covered with plaque and the thickness of plaque. The score for the tooth was obtained by adding the gingival and occlusive scores for each half (thickness multiplied by coverage). The sum of the tooth scores on one side of the jaw was termed “the total tooth score” and the whole mouth mean score is the average of the total tooth scores for each animal. On Day 0 each beagle was stratified according to high, medium and low plaque accumulation and then randomly assigned equally to either the treatment and control group. An average volume of 7 ml of Chlamydomonas reinhardtii concentrated algal paste, harvested live, approximately 10⁷/ml, strain CC-741 wild-type was applied topically with a sterile 12 cc syringe daily, 2 hours after feeding, to the teeth of each beagle in the treatment group. The control beagles received no treatment. All dogs in the study were fed a standard dry diet. Daily application of algae paste resulted in a 6.8% (SD 2.1) reduction in mean plaque scores compared with control beagles that received no treatment. Table 5 demonstrates that when the plaque scores are rank ordered, the paired comparisons showed the same plaque scores for the highest 6 beagles in the treatment and control groups, while the remaining 9 beagles in the treatment group all had lower scores than their comparative control group ranked pair. Further, the treatment group had the lowest overall plaque scores of 5.5 (2 beagles) compared to the lowest score of 6.6 in the control group. These data indicate that Chlamydomonas algal paste contacting the teeth of beagles reduces plaque formation.

TABLE 5 Plaque scores in Beagles (control and treatment groups) Dog Control Treatment 1 12.1 12.1 2 10.9 10.9 3 10.8 10.8 4 9.5 9.5 5 9.2 9.2 6 9.0 9.1 7 8.9 8.4 8 8.8 8.3 9 8.7 7.1 10  8.6 6.9 11  7.4 6.8 12  7.3 6.5 13  7.2 6.2 14  6.7 5.5 15  6.6 5.5 Average 8.8 8.2 Stand. Dev. 1.6 2.06

Example 4 Plaque Reduction Assay

a. General Test Design. To evaluate the various algae preparations a series of at least 3 screening tests will be performed to identify preparations for the prevention of dental plaque formation in animals. The screening tests will be designed as 7-day longitudinal studies with parallel groups of 5-10 animals. This will be followed by a complete crossover test to demonstrate the anti-plaque potential of the preparations selected from the screening tests.

b. Test Procedures. Each screening test will be designed as a one-week (7-day) clean tooth longitudinal test design. The test agents will be applied to the animals' teeth 3 times daily M-F and 2× daily on the weekends with applications separated by at least 2 hours. Experimental procedures will be conducted using GLP guidelines. The animals will be fed a nutritionally complete commercially-available dry dog food (Purina Dog Chow) at approximately 10:00 a.m. daily.

Prior to the initiation of each study the animals will be given a complete dental prophylaxis to remove all exogenous deposits (plaque, calculus, stain, debris) from the surfaces of their teeth. On the day each screening study will begin, the animals will be given Atropine (0.04 mg/Kg) by s.c. injection 20 minutes prior to the anesthesia. A certified laboratory animal technician will anesthetize the dogs with Butorphanol (0.15 mg/Kg) and Medetomidine (0.025 mg/Kg) I.M. followed by Ketamine HCL (5.0 mg/Kg) I.M. The animals will then be given a thorough prophylaxis. Following the dental prophylaxis, the animals' teeth will be imaged using the QLF System. The animals will then be given Atipamezole (0.05 mg/Kg) I.M. as an anesthesia reversal. The animals will be evenly stratified by block design into the desired number of groups of at least 5 animals per group. The animals will be balanced on the basis of plaque data obtained from the most current plaque-forming rate study. Considering the number of preparations to be evaluated, it is expected that each screening test will involve 5 groups with 5 or 6 animals per group. The test materials will be topically applied individually to the animals' teeth as an aqueous slurry using a syringe. Three (3) treatments will be given on week-days (Monday-Friday) and two (2) treatments will be administered on Saturday and Sunday; only one treatment will be given on the day the animals are prophied. The treatments will be performed at approximately the same time every day with 2-hour intervals between treatment applications. Each treatment group will have a coded beaker, which is designated for that treatment only. Each test group will have a color-coded tag attached to the animal's cage to correspond with the coded test group. The test solutions will be applied to all of the maxillary and mandibular teeth in their assigned treatment group. A 5 cc syringe will be used to apply the solution. Specifically, 2.5 cc of each test solution (within the appropriate group) will be evenly dispersed to each hemi jaw over the teeth to be evaluated and allowed to pool in the mandibular region. No attempt will be made to prevent the animals from swallowing the solutions. Care will be taken to prevent the disturbance of naturally occurring plaque. On the designated examination day, 7 days after initiation of the treatment regimen, the animals will be examined by block in a random sequence to avoid systematic bias. The animals will be anesthetized as previously stated, taken to the examination area by a certified laboratory animal technician.

The animals will then have their teeth imaged using Quantitative Laser/Light Fluorescence (QLF). The animals will then be examined for oral malodor, and disclosed plaque. Examiner observations will be recorded on prepared exam forms by the recorder who is not directly involved in the examinations. Baseline Quantitative Laser Florescence exams will be done immediately following the dental prophylaxis and after 7-days while the animals are still under anesthesia. The animals will be examined in a random sequence to avoid systematic bias. The examinations will be performed independently by an experienced QLF examiner. Specifically a hand piece utilizing a high intensity halogen light source, a video camera and a mirror for focusing, will be placed on the buccal side of the each of the following teeth:

Maxilla: I₃, C, P₂, P₃, P₄, M₁ Mandible: C, P₂, P₃, P₄, M₁

The QLF hand piece is coupled to a computer to permit visual viewing and recording of the images. The distance and angle of the QLF hand piece will remain essentially constant for each tooth imaged using the video repositioning (VidRep) program at 90-95%. A Halimeter will be used to measure Volatile Sulfur Compounds (VSC). The sampling tube will be placed parallel to the buccal Maxillary P₄. Cheek mucosa will be kept away from the end of the sampling tube and the animal's mouth closed. The highest reading after a 10-second period will be recorded. Both right and left sides will be sampled. The score for the animal is the mean of these two readings.

For the visual clinical dental plaque examinations the plaque will be disclosed by applying the undiluted disclosing solution (Red Cote; John O. Butler Company; 1.5% D&C Red No. 28) to the buccal surface of each tooth with a syringe and immediately rinsing with water. The gingival and occlusal half for each tooth will be scored. The teeth that will be examined will be:

Maxilla: I₃, C, P₂, P₃, P₄, M₁; Mandible: C, P₂, P₃, P₄, M₁

The amount of the buccal surface covered with dental plaque will be visually graded using the following scale: 0=no observable plaque; 1=scattered plaque covering less than 24% of the tooth surface; 2=plaque covering between 25 and 49% of the tooth surface; 3=plaque covering between 50 and 74% of the tooth surface; 4=plaque covering more than 75% of the tooth surface. The thickness of the plaque will be estimated using the following scale: 1=Light; 2=Moderate; and 3=Heavy. The clinical plaque score will be a function of both the coverage and the thickness. The coverage score is multiplied by the intensity factor to give a gingival and occlusal score for each tooth. The gingival and occlusal values for each tooth are added together to obtain a tooth sum. The score for each animal is the mean sum for all teeth scored. These same procedures will be used for the complete crossover study. For the first leg of the study the animals will be randomized to either the test or placebo treatment and examined after the 7-day test period. The animals will then have a one-week “washout” period and then provided another dental prophylaxis followed by the initiation of the alternative treatment regimen. In this manner all animals will receive both the test and placebo treatments with the test concluded after the second leg or test period.

Example 5 Plaque Reduction Assay

Chlamydomonas reinhardtii concentrate live or freeze dried, or in combination with synergistic agents and various application methodologies will be used. This phase will run for a total of 7 days. Dogs chosen for use on the study will have their teeth scaled and polished upon initiation of the test (Day-7). Each animal will have plaque indices scored on Day 0 before dental cleaning. The scores will indicate the rate of plaque buildup for each animal when being fed only a standard diet. This Pre-Test information will be used to designate the animals in one of three groups so as to stratify the group as a whole to reduce variability for the Testing Period.

Day 0 through Day 14 will be the testing period in which the test article, along with a standard diet, will be offered on a daily basis to the dogs within the test group for evaluation of plaque buildup as compared to evaluation of the control group which will be offered only a standard diet.

A minimum of 20 animals (e.g., Purpose-bred Beagle dogs) 1 year of age and older will be used. Groupings will be determined by evaluating the animals' individual scores obtained from the pre-testing period. Based on individual scores, 10 dogs will be in the test group and 10 dogs will be in the control group. Each dog will have a unique ear tattoo and cage card for identification.

Healthy adult dogs meeting the above description will be eligible for the study. Before the start of the study, dogs will undergo an oral cavity examination for normal occlusion and presence of all test teeth. Dogs will be pair-housed as intended for this study prior to study initiation. Individual body weights will be measured and recorded upon initiation of the study, weekly throughout the study, and upon completion of the study. Standard colony diet will be meal-fed, checked daily, and supplied in appropriate amounts according to body weight prior to study initiation.

Dogs in the test group will receive the standard diet for one hour and the test article will be applied two hours after the standard diet is removed from the dog's enclosure. The volume of test article required is 10 milliliters per treatment dog per day to be topically applied with a sterile 12 cc syringe. The control group will not receive anything in addition to the standard diet. Food consumption will be recorded daily throughout the study.

A veterinarian will give a complete physical examination to all dogs prior to Day-7. Each dog will be evaluated as to general health, body and hair coat condition, and comments will be recorded. Two milliliters of blood will be taken from each dog to test for BUN, PCV, and TP at the physical examination if this data has not been updated within the last 6 months.

Each animal will have its teeth scaled and polished under general anesthesia on Day-7. Each animal will have a plaque index scored at Day 0 using sedation or short-acting anesthesia. The extent of plaque is to be recorded after staining with a disclosing agent and rinsing the tooth surface. The dogs will be offered the standard diet only during this time period.

Each animal will have its teeth scaled and polished under general anesthesia on Day 0. On Day 14, each animal will have plaque evaluated using sedation or short-acting anesthesia if needed. The examination of teeth will include the buccal surfaces and both sides of the mouth. Review will be limited to these nine teeth: upper jaw—incisor 3 (I3), canine (C), premolar 3 (P3), premolar 4 (P4), molar 1 (M1); lower jaw—canine (C), premolar 3 (P3), premolar 4 (P4), molar 1 (M1).

Oral malodor will be evaluated on Day 0 and Day 14 by using a Halimeter. Readings will be obtained by putting the straw end of the Halimeter into the dog's mouth, between the cheek and jaw. A pocket will be made and the lips will be closed around the straw to assure accurate readings. One reading will be taken on each side of the mouth, and will be recorded in ppb.

Plaque will be evaluated using a modification of the Quigley and Hein (1962) (Turesky, 1970) plaque index. The extent of plaque and plaque thickness will be determined by placing a disclosing agent on the teeth and rinsing the excess off with water. The teeth are visually halved horizontally into gingival and occlusal halves. Each half is given a score for the percentage of coronal surface covered with plaque and thickness of plaque. The score for each half is calculated by multiplying the coverage and thickness scores. Gingival and occlusal scores are then added together for a tooth score. The sum of the tooth scores on one side of the jaw is termed the total tooth score, and the whole mouth mean is calculated by averaging the total tooth scores for each animal.

TABLE 6 Plaque Scoring Method PLAQUE SCORING METHOD Score % of Plaque Coverage 0 No plaque detected 1  1-24 2 25-49 3 50-74 4  75-100 Score Plaque Thickness Disclosing Agent Color 1 Light Pink to Light Red 2 Medium Red 3 Heavy Dark Red

Qualified personnel will perform clinical observations twice daily in accordance with institutions animal care observation standards. All animals will be evaluated twice daily with reference to protocol for (Recognizing Pain, Stress, and/or Distress). Clinical laboratory diagnostic procedures will be performed as needed. Veterinary care will be given as appropriate to each individual animal in accordance with the Program of Veterinary Care.

Test Article may vary by each individual trial. Test article consistency will be sticky paste/gel that will be drawn from a container into sterile syringes. The test article will then be administered onto the teeth via syringe. The test article will be stored in refrigeration for the duration of the study.

With the exception of drugs used to anesthetize the animals for dental scoring and cleaning, vaccinations, drugs, and locally applied or lickable antiseptics should not be used for the length of the study. If an individual animal requires treatment as determined by the veterinarian, the Sponsor will be notified and the necessity of removing the animal from the study will be determined. The study will be stopped if the average weight change of the dogs is greater than −10%. If any dog loses more than 15% of its base (initial) weight, that dog will be evaluated by the veterinarian and removed from the study if the veterinarian deems it necessary to do so. The study may be stopped at any time at the veterinarian's discretion if the animals' health is at risk. A veterinarian will perform a necropsy on any animal found dead or euthanized to determine the cause of death or illness.

Variables to be measured will include the effect of Chlamydomonas reinhardtii on the formation of dental plaque, the effect of Chlamydomonas reinhardtii on the formation of dental malodor, and the effect of Chlamydomonas reinhardtii on the formation of dental calculus. Other variables to be measured include food consumption, body weights, and adverse reactions through daily observations. Statistical analysis will include individual t-tests, mean scores, and standard error functions.

Example 6 Molars Treated with Algal Paste

A total of 6 extracted human molars (a tooth in each group) were used for this study. These specimens were removed of soft tissue. A window was made on the surface of sound enamel specimen by nail varnish. These specimens were immersed into demineralizing solution (White, 1987) at 37° C. for 2 hours to produce the early artificial white-spot lesions. The whole surface of each molar was covered with an algal strain. After 5 minutes, each molar was shaken in a water bottle for 30 seconds and any surplus alga was rinsed off. The images of these specimens were acquired with a standard white-light dissecting microscope. Digital images of the molar prior to treatment and after rinsing were recorded. After the 30 second rinse, strains CC-1284, CC-741, and Phyvac WSSV-VP28 were not evident on the enamel surface lesion, suggesting a low level of enamel adherence. Strains CC-1284 and CC-2677 adhered to parts of the surface whereas CC-1952 covered the whole surface of the molar.

The experiment was repeated again, with the rinsing treatment repeated 6 times. CC-2677 was removed from the surface after the second rinse. CC-1284 and CC-1952 could not be removed after the sixth rinse, although adherence of strain CC-1952 to the tooth surface was greater than for CC-1284 (FIGS. 1 and 2).

The rinsing experiment was repeated a third time with CC-1284 and CC-1952. After the sixth rinse, digital images of specimens were made using the Quantitative Light-induced Fluorescence system (Inspektor-Pro 2.0.0.32, Inspektor Research System B.V., Netherlands). These images were analyzed with the measurement for red fluorescence using Inspektor-Pro 2.0.0.32. QLF images and its analyzed images are shown in FIG. 3. From these images it was calculated that after the sixth rinse, 16.60 mm² and 45.60 mm² of the molar surface was covered with cells of CC-1284 and CC-1952, respectively.

Example 7 Toothpaste

An exemplary animal toothpaste formulation for use in the compositions and methods described herein is below. Sample ingredients for the toothpaste are as follows (expressed as percent by weight): dental grade silica abrasive at about 10-12% (gives polishing abrasion and thickens toothpaste); dicalcium phosphate dihydrate at about 2-4% (dentifrice grade toothpaste polish and abrasive); pumice (a toothpaste polish and 1-2% abrasive); toothpaste thickening and binding agents, such as sorbitol at about 10-40%, polyethylene glycol at about 4%, carboxymethylcellulose at about 1%, glycerin at about 15%, flavor at about 1-3%, the algae composition at about 5% (or another effective amount depending on the intended application), and water sufficient for processing. Toothpaste formulations for humans may also include surfactants (cleaning and foaming agents). Toothpaste formulations for animals other than humans typically do not include surfactants. The formulation may also include about 2% sodium fluoride in a suitable form.

Example 8 Chew Treat

The algae composition as described herein may be added to raw hide as a chew treat to improve animal dental health. The raw hide can be made from cattle hides, horse hides, sheep skins, goat skins, buffalo hides or pig skins, for example. The raw hide may be cut into sections or strips. Alternatively, the raw hide sections may be ground into smaller pieces of about ⅛ inches to about ½ inches in diameter, for example, and dried. The algae composition may be sprayed onto the dried raw hide pieces. In this embodiment, the pieces can be placed in a rotating mixing drum and the algae composition sprayed onto the tumbling pieces or chews. Following the coating (spraying) step, the product will be placed on screens in racks and air dried. The resulting chew treats containing the algae composition may be molded into the shape of a animal chew treat.

Another exemplary approach is to mix the algae composition and dried raw hide with meat meal, bone meal, a binder such as malotdextrin, and/or gelatin. Water will be added in a quantity sufficient for processing. The formula will be heated, mixed, and placed into molds. After molding into suitable shapes, the product will be dried in an oven.

Example 9 Toothpowder

An exemplary powder formulation for use in the compositions and methods described herein is provided. According to the following formulation (components expressed as percent by weight), the ingredients are mixed well to make a fine powder, including calcium carbonate at about 75.0%, glycerin at about 10.0%, flavor at about 1.0%, propylparaben at about 0.005%, sodium laurylsulfate at about 1.3% (typically used only for formulations for humans), saccharin sodium at about 0.1%, the algae composition at about 5% (or another effective amount depending on the intended application), and water q.s. total 100%.

An additional exemplary toothpowder formulation with fluoride will be made by mixing together the following ingredients (components expressed as percent by weight), in the indicated proportions: microcrystalline aluminum hydroxide at about 86%, aluminum hydroxide (325 mesh) at about 5.00%, flavoring matter at about 0.60%, saccharin (soluble) at about 0.25%, sodium fluoride at about 0.10%, the algae composition at about 10%, and water. 

1. A method for reducing plaque on at least one tooth of an animal, the method comprising the step of causing the at least one tooth of the animal to be contacted with a composition comprising green algae wherein the composition comprising the green algae reduces the plaque on the at least one tooth of the animal.
 2. The method of claim 1 wherein the algae are in a form selected from the group consisting of a paste, a gel, a nugget, a pellet, a powder, and a liquid.
 3. The method of claim 1 wherein the algae are freeze-dried and are capable of being reconstituted.
 4. The method of claim 1 wherein the algae are a component of a product selected from the group consisting of an animal treat, a dressing for an animal food, an additive for water, and a component of a chew product.
 5. The method of claim 1 wherein the algae are genetically modified.
 6. The method of claim 1 wherein the algae composition further comprises an antimicrobial.
 7. The method of claim 1 wherein the algae composition further comprises a plaque-reducing agent.
 8. The method of claim 1 wherein the algae are Chlamydomonas reinhardtii.
 9. The method of claim 1 wherein the algae are selected from the group consisting of live algae, dead algae, and combinations thereof.
 10. The method of claim 1 wherein the animal is a domestic animal.
 11. A composition comprising green algae wherein the green algae composition is adapted for contact with at least one tooth of an animal.
 12. The composition of claim 11 wherein the algae are in a form selected from the group consisting of a paste, a gel, a nugget, a pellet, a powder, and a liquid.
 13. The composition of claim 11 wherein the algae are freeze-dried and are capable of being reconstituted.
 14. The composition of claim 11 wherein the algae are a component of a product selected from the group consisting of an animal treat, a dressing for an animal food, an additive for water, and a component of a chew product.
 15. The composition of claim 11 wherein the algae are genetically modified.
 16. The composition of claim 11 wherein the algae composition further comprises an antimicrobial.
 17. The composition of claim 11 further comprising a plaque-reducing agent.
 18. The composition of claim 11 wherein the algae are Chlamydomonas reinhardtii.
 19. The composition of claim 11 wherein the algae are selected from the group consisting of live algae, dead algae, and combinations thereof.
 20. The composition of claim 11 in the form of a kit. 